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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

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26                                 ALASKAN GLACIER STUDIES
building of the plain is less active than formerly. To the northwest of Yakutat Bay the coastal plain is a mere fringe around the margin of the Malaspina Glacier and in two places is entirely absent, where the sea comes in contact with the glacier at Sitkagi Bluffs and Icy Bay. What the condition is beneath the Malaspina ice plateau is unknown.
In lie immediate vicinity of Yakutat Bay the glaciers are greatly shrunken, and, excepting on the periphery of the Malaspina Glacier the construction of the foreland is progressing very slowly. Yet this is the broadest part of the coastal plain, testifying to the former great activity of deposit by glaciers and glacial streams. That the Yakutat Bay inlet exists in spite of the former activity of deposit is doubtless the result of the energetic erosion by the formerly expanded glaciers; and in the foreland area itself the existence of the bay is probably due to the occupation of the area by an expanded ice bulb which prohibited deposit there while it remained, and whose recession was so rapid that deposits failed to fill the depression. That deposit was in progress on the outer or ocean margin of the expanded bulb that filled Yakutat Bay is proved by the presence of a crescentic shoal completely across the mouth of the bay, on portions of which the ocean waves break in times of storm. Terminating, as it did, in the open ocean, the expanded Yakutat Bay Glacier was unable to deposit as rapidly here as in the case of glaciers ending on the foreland, for much of its supply of debris was borne off into the open ocean in icebergs and spread over a broader area than that reached by streams charged with glacial de*bris.
On the inner margin of the coastal plain the mountains rise abruptly. To the southeast of Yakutat Bay the Fairweather Range rises in magnificent proportions, almost from sea level, to elevations of from 10,000 to 15,000 feet or more, broken only by the glacier-skirt Alsek valley and by a series of broad glacier-filled troughs. With snowline descending to within 8000 or 4000 feet of sea level, with glaciers in all the valleys, and with its lofty peaks of varied form and elevation, this is one of the grandest mountain panoramas in the world with the whole mountain range, from crest to base, almost at sea level, exposed to view as one sails along the coast for a full day (see frontispiece). This panorama is perhaps not even rivalled by the St. Elias Range itself, which, though higher, lies farther away, with Malaspina Glacier between it and the sea. Between Mt. St. Elias and the Fairweather Range proper the lofty mountains of the continuous chain lie farther back from the coast and are separated from it by lower mountains and by the fringe of coastal plain already described. These foothills rise to no great height, rarely reaching elevations above 5000 feet; but their crests are snow-capped, while glaciers lie in most of the valleys; and through the larger ones descend great glaciers, fed among the higher mountains of the St. Elias Range farther inland. Both arms of the Yakutat Bay inlet pierce the foothills, making a complete cross section through them, and extending to the base of the crystalline mountains of the St. Elias Range. Here the mountains rise rapidly in elevation, reaching heights of from 10,000 to 16,000 feet within a few miles of the shore. From the shores of this bay the full grandeur of the St. Elias Range is seen perhaps at its best, and certainly from a central vantage point. Mt. Fairweather (15,330 feet) is visible to the southeast, the striking pyramid of St. Elias (18,024 feet) to the northwest, Mt. Logan (19,500 feet) to the north, Mt. Hubbard (16,400 feet) to the northeast, Mt. Vancouver (15,617 feet), Mt. Cook, (14,700 feet), Mt. Seattle (10,000 feet) and a multitude of other great peaks, many of them unnamed, still nearer at hand, while in the foreground are innumerable lesser peaks.